UNSTOPPABLE: Tim Tebow, back on the field two weeks after suffering a concussion, tries to shed a tackle by LSU's Patrick Peterson during the No. 1 Gators' 13-3 win in Death Valley last night. Getty Images

BATON ROUGE, La. — The worst part of returning from a concussion that left the nation cringing wasn’t when Tim Tebow took a dead-on shot to the chest that whiplashed the back of his helmet onto the Tiger Stadium field.

“Actually I liked it,” a grinning Tebow said of the first-quarter hit. “It was the first time I got hit. Everything felt good. So I like, “All right, I’m ready to go.”

Tebow and the Gator nation didn’t know for certain until yesterday morning that their star quarterback would go in last night’s 13-3 slugfest win over No. 4 LSU before a Death Valley-record crowd of 93,129.

But Tebow had a pretty good sense he had recovered from the concussion he suffered two weeks ago when he didn’t vomit on the No. 1 Gators’ turbulent flight from Gainesville to Baton Rouge.

“I turned up the air and was holding on to the seat in front of me,” Tebow said as he pantomimed clutching the back of chair.

“I didn’t get sick, which was a great test for the doctors,” he added.

No, the ones who walked away ill on this night were the Tigers (5-1), who saw their streaks of 21 straight home wins and 32 straight Saturday night triumphs here ended. Florida (5-0) continued its lofty quest of posting the school’s first undefeated season.

“I give Tebow all the praise in the world to play in that circumstance,” LSU linebacker Kelvin Sheppard said. “He completed passes. He ran the ball hard. I take my hat off to Tim Tebow.”

A lot of the praise for Florida’s win belongs to the defense. The Gators held LSU to a mere 162 yards in total offense and posted two monster fourth-down stops.

“One of the best efforts I’ve ever seen containing athletes,” said Florida coach Urban Meyer.

In a bodacious testament to his remarkable inner strength and sheer grit, Tebow played fearlessly. He wore a motion sickness patch behind his right ear after the game, not because of any residual effects of the concussion but because of motion sickness.

Patrick Peterson blasted him on the fifth play of the game. He popped right up. The Gators medical staff exhaled. Florida drove down the field and got a field goal.

After LSU tied it 3-3, Tebow opened the next drive with a scramble. Tebow doesn’t remember the hit that drove the back of his head into lineman Marcus Gilbert’s leg two weeks ago, but no Florida fan will forget that 8-yard scramble as he eluded five LSU defenders.

Tebow ended the drive by tossing a 24-yard TD pass to Riley Cooper for a 10-3 lead with 50 seconds left in the second quarter. It was Tebow’s 122nd career TD, tying him with former Florida star Danny Wuerffel for the most in SEC history.

“It’s never been safer to play high-velocity impact sports,” concussion expert Dr. Tony Strickland told The Post on Friday. “We’ve moved away from the ‘follow-my-finger, Ouija board diagnosis of concussions.’ ”